Radio apparatus



July 1'7, 1928. 1,677,589

J. H. HALLBERG RADIO APPARATUS Fiied Nov. 1a. 1922 bodying theconstruction Fat-ented July 17, 1928. I

' UNITED ,-STATES i 'Josnr HENRI]! HALLCBERG, or new Yonx, NrY.

RADIO errenarus.

' Application filed fiovember 1a, 1922. Serial No. 601,796.. I

My invention relates to improvements in radio transmitting and receivingapparatus. The object of my invention is to provide means whereby radiomessages can be. transmitted and receivedclearly without ex} traneousnoises and where the samefcanbe.

amplified, so they can beclearliyheard with orwithout the use of theordinary headpiece telephone receiver,

My invention also does away with I g The links, 6 and 7 are providedwith pins,

necessity of using an exterior antenna.

Further objects and advantages of my in-- vention will be broughtouthereinafter. Referring to the drawings: f

Fig. 1 is a top view in: sect'on of em. end of my cabinet. 3 V

Fig. 2 is an end View. of my cabinet, looking' at Fig. 1 from the left,with; the end panel removed. t v

Fig. 3 is amodification of my invention, showing a top, view partly insection, of one end ofmy cabinet. I V

Fig. 4 is a left hand, front view of one of the preferred forms of mycabinet, em-

shown. in Fig. 3.

Fig. 5 is a front view 7 end of my cabinet, showing the, door of thesame in its extreme open-position. I A

Fig. 6 is an edgewise viewof-thedoor shown in Fig. 5, looking'at thesame from the left.

Fig. 7 is a detail View of the receiving coil supports. j a Fig.8 is adetail View of F1 ."zalooking at the same from the top or ottom.

F -9' is a detail view in perspective, showing method ofmounting thereceiving coil on the supports. i

r In this application I have disclosed my invention as applyingprincipally to means for receiving radio transmissions, I, I wish itunderstood, however, that there are many features disclosed herein whichmay be applied tothe transmissionof radio messages.

Referring now to the drawings, itwill be seen that the compartment, (2)is provided with a door, 4','which may. also serve to support and adjustthe position of the receiving coil, 3 or loop antenna. I I have foundafter considerable experimentation that by forming my receiving coil ina peculiar way, as will hereinafter be described, it is possible for meto construct it within the dimensions of the door, 4.

In the form shown in Figs. 4 and 5 I mount of the left hand this coil,3, on the insideof the door, 4, of the cabinet. This door, 4, is mountedon the front of the cabinet and controls access to the compartment, 2..At the center top and the center bottom of the door, 4, and centrallypivoted thereto on a vertical axis, I provide links, 6 and 7, (Fig. 6).One end of theylinks is pivoted to the door as at 8 and 9,-the other endof the links is pivoted to the door frame, as at 11 and 12.

13 and 14, respectively, which rotate in sock I ets 15 and 16. Thesockets are mounted on the upper and lower edges of the door 4. Theopposite ends of the links, 6 and .7, are. providedsimilarly withpins,17-and 18,

respectively, which rotate in sockets 19-and 20, mounted in the top andbottom of the door frame, respectively. It is seen at once that thisconstruction gives the door, 4, a freedom of motion, .such that it canbe placedyin .any position around its central vertical axis, therebypermitting it to be adjusted in the proper plane to receive mes sages,andalso permits the door to be openedand closed, as if it were onordinary hinges. v Mounted on the inside of the door, 4, is the coilsupporting frame, 21, (Fig. 6), con sisting of four strips, 23, arrangedin two pairs, each pair located onthe diagonal of the door, and the twopairs or; halves of the frame being secured to the door, perpendicularlyto each other, by a centrallylocated' bolt, 22. p t V In order tosecurethe best. results I have found it necessary to make this frame andwind it in a certain definite-way. By following this. method I am ableto secure superior results to those obtained by any other method knownin this art. I will now of winding the coil, 3, thereon.

In Figs. 7 and 8, I have shown one end of a pair ofthe strips, 23, 23,referred to above, forming a part of the frame, 21. These strips I.makeof some suitable insulating material, such as wood, bakelite, etc,each strip, 23, being of rectilinear-cross section,

[with its width appreciably greater than its thickness. These strips,23, I mount side by side, as shown in Fig. 7, the ends being securedtogether as at 24, Fig. 7 while the strips at their longitudinal centerare spaced apart, one from the other, as best shown in Fig. 5, providingthereby, a means of securing the frame, 21, to the door, 4, by means ofthe bolt, 22, already referred to. Upon both edges of the strips, 23,comprising the frame, 21, I provide lateral'notches diagonally disposedthereon, and of a suitable depth to receive the wire forming the coil,3. These notches run diagonally toward the center of the strip, 23. Thecoil, 3, consists of an electrical conductor, a copper wire, forexample, wound spirally on the frame, 21, Fig. 9, in'such a way that thewire runs from one side of a strip, 23, to the opposite side of the nextstrip, and thus continues to alternate from one side to the other of thesuccessive strips, for three quarters of one turn, the last quarter ofthe turn taking place on the same side of two successive strips.

In order to make this clear I will number the ends of the strips, 23,composing the frame, 21, separately, as shown in Fig. 9, Starting at theinner end, 25, the coil, 3, is wound as follows: upper edge 26, loweredge 27, upper edge at 28, upper edge at 29, lower edge at 26, upperedge at 27, lower edge at 28, lower edge at 29, upper edge at 26, loweredge at 27, upper edge at 28, and.so on. From this it will be seen thatthe coil, 3, is composed of four sections, forming a square grid. Inthree of the sect-ions, the proximate wires are in diagonal relation toeach other, while in the fourth section, the wires are in parallelrelation to each other. I will not attempt to explain the reasons whythis form of receiving coil works better than any of the others, butsuflice to say that it does excel the other forms, and to a very markedextent.

The terminals 30 and 31, of the coil, 3, areconnected electrically tothe upper and lower sockets, 15 and 16, respectively, through suitableconnections, as shown in Fig. 5. The sockets 19 and 20, in the doorframe, are also provided with electrical connections, 21 and 22, whichconnect the coil, 3, to the receiving apparatus in the cabinet.

The advantages of a receiving coil mounted as just described, outside ofits compact size, will be appreciated by anyone familiar with theradio'art, in that upon opening the door, 4, and swinging the samearound its pivots, 8 and 9, the coil, 3, mounted thereon can be adjustedto be responsive to radio transmissions approaching from any direction.The position of the door, 4, and the coil, 3, secured thereto, can beused also as a modulating means to control the intensity of messagesreceived, for the reason that the messages will vary in their amplitudefrom zero to a maximum through 90 degrees motion of the door on itspivots, 8 and 9, and therefore all modifications are available betweenthese two limits.

4, of the compartment, 2, as the means of supporting the receiving coil,3. This meth- 0d of supporting the coil, 3, however, at

times may be an objection as the door, 4, may extend out into the room,when in use, depending of course, upon the direction from which themessages are being transmitted. In order to overcome this possibleobjection I have shown'in Figuresl and 2a modification thereof. In thiscase the coil, 3, is mounted on the inside of a movable panel, 5, thepanel 5, and the coil, 3, being pivoted by links, 6 and 7 similarly tothose shown in connection with the door, 4, and is provided with otherdetail parts, the same as described above, as applying to the door, 4.The panel, 5, in this case, I prefer to mount on the end of the cabinet,as distinguished from the front thereof, as in this position it will notprotrude-into the room, when in use. The cabinet is placed against thewall, in most instances, near the corner of the room, and the outerpositions of the panel, 5, would not, in this case, be an objection.

In the above, I have shown and described two positions'for my receivingcoil. 9 I wish it distinctly understood, however, that I do not limitmyself to any position in which I may place or operate my receivingcoil. Manifestly, by making the cabinet 21; little longer, and ifsuflicient space were provided, I could mount the coil inside thecabinet. I could also adjust the coil, by turning it on pivots, such forexample, as 8v and 9, which pivots, in this case would have sockets permanently secured to the top andbottom of the compartment, provided forthe receiving coil inside the cabinet. In this case the coil could berotated into adjustment, either by having access to it through anopening or door in front of the cabinet or by extending a controllingknob or wheel through the top of the cabinet, 32. V

I have found, as a result of a considerable amount of investigation andexperimentation that by employing the above disclosed methods comprisingmy invention I am enabled to produce superior results to any of themethods now employed. or known to the art.

I do not limit myself to the construction described above nor to thespecific uses given, as there may be many modifications made, in theparts and additional uses found, (such,

for instance, as recording on the phonograph disc the messages receivedby radio so as to make a permanent record thereof), which would comewithin the scope of my invention. The disclosure above is simply oneembodiment of my invention, as required by the statutes.

Having described the same so thatanyone skilled in the art'to which itpertains can make. and useit, What I claim as my invention, and wish tobe secured by Letters Patent, is a 1. An antenna for radio receiving apa-' ratus comprising a carrier having para lel top and bottom edges, anelectrically conducting loop wound on the carrier, conducting bearingsat mid-points on the top and bottom edges of the carrier upon which thecarrier can freely rotate, connections from the conducting loop to saidbearings and links hingedly mounted on a support for said antenna havingpivoting means thereonwhereby said loop is rotatably mounted andconductively connected to said support.

2. An antenna for radio receiving apparatus consisting of a frame onwhich is wound a coil of Wire, mounted on a door to a cabinet,connection means between the door and the cabinet including supportingstrips hingedly mounted on the cabinet, conducting means for rotatablypivoting the door about an axls substantially at its middle por tion,mounted on the strips and an electrical circuit connected with said coilthrough said conducting means.

8. An antenna for radio receiving apparatus consisting of a frame 'onwhich is wound a coil of wire, mounted on a door to a cabinet,connection means between the door and the cabinet,,including supportingstrips hingedly mounted on the cabinet and means supported by saidstrips for rotatably

